Display Settings:

Format

Send to:

Choose Destination
Free Radic Biol Med. 1999 Jan;26(1-2):148-61.

Photoreduction of the fluorescent dye 2'-7'-dichlorofluorescein: a spin trapping and direct electron spin resonance study with implications for oxidative stress measurements.

Author information

  • 1Dipartimento di Chimica Organica A. Mangini, Universit√† di Bologna, Italy.

Abstract

The photoreduction of 2'-7'-dichlorofluorescein (DCF) was investigated in buffer solution using direct electron spin resonance (ESR) and the ESR spin-trapping technique. Anaerobic studies of the reaction of DCF in the presence of reducing agents demonstrated that during visible irradiation (lambda > 300 nm) 2'-7'-dichlorofluorescein undergoes one-electron reduction to produce a semiquinone-type free radical as demonstrated by direct ESR. Spin-trapping studies of incubations containing DCF, 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and either reduced glutathione (GSH) or reduced NADH demonstrate, under irradiation with visible light, the production of the superoxide dismutase-sensitive DMPO/*OOH adduct. In the absence of DMPO, measurements with a Clark-type oxygen electrode show that molecular oxygen is consumed in a light-dependent process. The semiquinone radical of DCF, when formed in an aerobic system, is immediately oxidized by oxygen, which regenerates the dye and forms superoxide.

PMID:
9890650
[PubMed - indexed for MEDLINE]

LinkOut - more resources

Full Text Sources

Other Literature Sources

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk